#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 1e6 + 5;

int n, m;
int a[N];
void solve() {
  cin >> n;
  rep(i, 1, n) cin >> a[i];
  map<int, int> mp;
  int l = 0, r = 0, ans = 0;
  while (r < n) {
    if (l) mp[a[l]]--;
    l++;
    while (r < n && !mp[a[r + 1]]) {
      mp[a[++r]]++;
    }
    ans = max(ans, r + 1 - l);
  }
  cout << ans << endl;
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}